Thursday, June 29, 2017

Field Day was a big success for me this year. I was in category "1E" which meant that I was home in the air conditioning, but doing my bit for emergency service by using a gel cell as my power source. A SOLAR CHARGED gel cell. So don't anyone call me a slacker, OK? I was on my HW-8 and made a total of two contacts. The second was with AH6AX. I wasn't fooled -- I knew they weren't in Hawaii. But the op gave me his home call: WB8YYY. Curt is a SolderSmoke listener. In a follow-up e-mail he alerted me to the web site of AA8V. Great stuff. Thanks Curt. Here is the AA8V workshop: http://faculty.frostburg.edu/phys/latta/ee/workshop/workshop.html#electronics1

Monday, June 26, 2017

At Dayton, Bob Crane interviewed our friend Farhan VU2ESE. Farhan shared insights on the BITX, the Minima and future rigs. Farhan was inducted into the QRP Hall of Fame at this year's FDIM event. You can listen to the interview here: http://soldersmoke.com/FDIM17VU2ESE.mp3

Sunday, June 25, 2017

SPRAT 161 (Winter 2014/15) had a very intriguing article about the Heath HW-8 by Dave M0CEM. Dave wrote about a possible design error in the active filter of the receiver. The center frequency and gain shift significantly when you switch from "Wide" to "Narrow." I was very interested because for many years I have noticed this problem in my own HW-8. I just left it in "Wide" and never used the more narrow filter.

Dave did some excellent circuit detective work and determined that the problem was R24. He prescribed a change: instead of 82k it should be 49.8k. The placement of a 130k resistor across the 81k R24 would have the same effect.

Yesterday morning I installed Dave's mod. I did as he suggested and put a 130k resistor across R24. Brilliant! What a difference! In the past, I noticed a significant degradation in signal strength when I put the filter in the "Narrow" position. This doesn't happen now -- the response obviously does narrow, but the center freq stays the same.

It is really amazing to me that the Heath engineers made this error, and that it went uncorrected for so many years. There have been many, many modification articles for the HW-8 over the years, but I haven't seen any that really address this problem. If anyone has more info on how this design error happened and why it went uncorrected for so long, please let me know.

Thanks to Dave and SPRAT for getting us back on the straight and narrow.

Saturday, June 24, 2017

Last Saturday I put the Tuna Tin Two Top together with my Herring Aid Five 38 (year) Special and the Indian key that Farhan gave me. I discovered that some of my 40 meter CW FT243 crystals had disappeared into the entropy of the shack. But I was able to find one for 7050 kHz. That was a bit of good luck because it turns out that 7050 is the frequency of a congenial group of operators known as the Straight Key Century Club. I felt right at home. I have been inducted. My SKCC number is 17272. Very QRP, don't you think? It is almost a Vanity SKCC. Clearly, TRGHS. I have been having excellent luck with this 7 transistor rig. I have had one contact each day since I put it on the air, all of them in response to my CQ calls. I've worked: K1PUG Hank in Connecticut (twice)W8HOG Jerry in OhioWA4GQG Kevin in North CarolinaWA2AAW Frank in New YorkKM4FO Dwight in Kentucky

This morning I added a little piezo buzzer for sidetone. I am thinking of adding a VFO to the Tuna Tin.

Friday, June 23, 2017

Close in color don't you think? Dave Ishmael WA6VVL noted the NC-270 receiver's color was "Cosmic Blue." Indeed, National noted the unusual color ("outstandingly different") in its advertising. This now-rare receiver was produced between 1960 and 1964, so it could have influenced Pete. Of course, the CK-722's color could also have played a role...

BTW, shouldn't we ask Pete to get out his guitar and give us some "Juliano Blues"? We need some music to go with the paint.

Thursday, June 22, 2017

In the late 70's the community had a fetish for canned seafood and DC receivers. Do you remember the 80m Sardine Sender ? How about YL Special ? (QST Oct and Jan 1979.) I married them together in a kludged-together box made out of a bent rack-mount panel and defunct aluminum chassis cover.

The bottom board is the rock-bound transmitter. The upper deck is the receiver board. The little mini box contains VFO (so cute.) The 741 audio board is tucked under the scrounged ¼ inch jacks.

Super simple, but lots of fun. It's a handy rig for the week at the beach, although 80m propagation and beach week are 6 months out of phase.

Sunday, June 18, 2017

Haunted by a fear of rapid expulsion from the QRP Hall of Fame, I decided that I should immediately do something to establish some form of QRP street cred. Looking around the shack, I realized that all of the ingredients were there: My Herring Aid Five Direct Conversion receiver (completed after only 38 years), my Tuna Tin Two transmitter, the VU2XVR key that Farhan gave me, one 7050 kc FT243 crystal. I put it all on a piece of scrap plywood. A couple of nice connectors from W8NSA supported the DPDT T/R switch and the coax connector. I keep the receiver LO running all the time.

Now, let's be clear: running 250 milliwatts, rock bound with a Direct Conversion receiver that tunes both sides of zero beat is not for the faint of heart. The log book does not fill up rapidly. But hey, I made one contact the following morning. K1PUG said I was 559 in Connecticut.

Friday, June 16, 2017

Eric 4Z1UG had a great "QSO Today" interview with Richard Fisher KI6SN. Richard mentioned his method for making project boxes. The commercial versions are getting very expensive, and the used ones are now hard-to-find at hamfests. So use Richard's technique to roll your own!

Wednesday, June 14, 2017

Enjoyed the recent Hamvention interview with Ed Hare and your comment about him and a Heathkit HW-8 QRP rig. I recently rescued the HW-8 I bought on eBay that had been sitting in my project queue for several years. As I was refurbishing the rig I found that John KC9ON (http://kc9on.com) has several HW-8 mods that are very reasonably priced and I incorporated in the the refresh. They included replacements for the audio amplifier and the T/R relay, the “miniYAK” electronic keyer that I installed internally and built-up a external control dongle for the keyer. Cleaned up the additional audio filter that the previous owner had installed (ancient MFJ CWF-2 op-amp filter, surprisingly still available from the MFJ Vectronics brand, model VEC-820K) and did a complete realignment of course. The T/R replacement includes provision for a red and green LED that indicates that the rig is in the receive mode (green) and transmit (red); I was able to mount them directly behind the relative output meter using a piece of plastic drapery hardware (always pays to keep that kind of stuff!). Finally installed a fresh S-meter mod.

RF output is ok on all the bands except for 15m and I still need to figure that out. Getting rid of the old Molex power connector and replacing it with a Powerpole was a real plus I thought. Have swapped out the PA transistor with several different types but the one the last owner substituted in seems to be the best (ECG488). Have to admit I’ve never been a devoted QRP guy but love the community for it’s technical bent but since I’ve been looking for some new challenges I thought this would be a enjoyable one.

As you’ve pointed out Mike Bryce’s HW-8 handbook is a must have for anyone updating their radio and there is also a seminal 2-part article series in CQ magazine that probably started the mods craze; they appeared in the August and October 1977 issues of CQ.

Here are some pix of the clean up process and shows I’m not afraid to drill holes in a boat anchor to make it more useable!

73 - Dino

Here’s the new audio board installed:

The additional audio filter with the new 5-pole selectivity switch put in by the previous owner…had to add some audio coupling caps and clean up all the wiring. The plastic piece over the meter was from some old drapery hardware and it now holds the RCV/XMT green/red LEDs:

I replaced the original S-meter mod with a proper terminal strip (old parts were just hanging in the air).

Here’s the solid state T/R circuit that replaced the mechanical relay:

Tuesday, June 13, 2017

I was on 40 SB tonight talking to Don KC5YR. He is the creator of the web site known as the Moxon Antenna Project: http://www.moxonantennaproject.com/ That site had this great picture of OM Les Moxon, inventor of the wonderful antenna that bears his name. I also found this old QSL card that shows some of Les's homebrew gear. Les has been a Silent Key for many years now, but his legacy lives on.

Sunday, June 11, 2017

There is no real connection to radio here, other than the fact that some of us are in this guy's age group, and that we have had a few Dos Equis Guy memes on the blog. But do yourself a favor and spend a few minutes with this article. You will be glad you did.

Saturday, June 10, 2017

Seeing the topics for regional operator lists got me thinking. If words are good, pictures are better. I set up a google map that you can add yourself too to help visualize where everyone is located. I was going to add people that responded to the other topics but out of respect for privacy (and my laziness) this should be entirely opt in only. The map is only accessible with the link below. The interface is reasonably intuitive but I will do my best to explain how to add yourself.go to

hit enter or click the magnifying glassverify the location displayedclick add to map at the bottom of the box that pops upnow click the pencil/edit icon at the bottom right of the boxchange the highlighted address to your call sign and click save at the bottom left of the boxyou can also add more information to your spot if you choose tobookmark the link and check back as more people add themselvesI am making this sound much more complicated than it is. If anyone can describe the process better please do.

Thursday, June 8, 2017

I believe Harold is in Elk Grove California. Is there anyone out there who could help him? If so, please send me an e-mail at soldersmoke@yahoo.comBill I'm a very elderly ex-ham living in Elk Grove and my current project is putting together a World War II military surplus IFF. This requires that I solder cable to small circular connectors and I no longer possesss the eye-hand coordination to do this. Do you jnow of any ham who can help me with this-he or she would be reimburses, of course Thanks for you your help 73s Harold S Meltzer ex W2OZX.

Wednesday, June 7, 2017

Above you see another gem from the Manassas hamfest. I didn't know what this was. And I don't think the seller knew what it was either. I think I gave him 5 bucks for it (as it turns out that is close to the original 1925 price). It was only in the course of looking up yesterday's Philmore Fixed Crystal Detector that I happened to spot a picture of this thing. There is not much to it. That nice dial is mechanically connected to a sweeper arm that runs along a big coil. The galena and cats whisker were apparently held in place by the Fahenstock clips on the front. Leon Lambert made these things in Witchita Kansas around 1924. He started making them without the fancy wooden box, but one report says he found a good source for the enclosures:

In 2004 Dale Davenport wrote:Leon Lambert's crystal sets show up maybe as or more often than most other brands from that time period apparently, particularly in the Midwest, There are quite a few variations though: some have a little metal tag tacked on, usually on top front center, some do not have a tag at all. Detectors vary some as well and I've seen them with Erla fixed detectors. One thing is more or less constant it seems, and that is the little wooden boxes they are mounted in. I cannot verify the story other than from observations, but was told quite a number of years ago that the boxes the Lambert sets are mounted in were used to ship sticks of chalk, packed in saw dust, to schools. Lambert supposedly had a deal with someone with the local school system to acquire these as they were emptied. I have owned one example, and have seen other examples of these sets that show some pressure marks on the flat sides, near the corners, where they apparently were packed in bundles, and the strapping tape used to secure the bundles left an impression. This seems to indicate that the story might be true and they might be leftover marks from the box's days as a chalk shipping box.Has anyone else heard the story or can anyone else offer more details on this theory? From: http://www.antiqueradios.com/forums/viewtopic.php?t=36735Here's a picture of the unboxed version -- you can see here where the galena went:

Tuesday, June 6, 2017

I was at the Manassas, Virginia hamfest on Sunday. An old timer had a box of crystals for sale. It was obviously the kind of "box of rocks" that many of us have in the shack. There was a very wide variety of crystal packages in there, perhaps the widest range of possible styles. In among the modern computer crystals and WW II FT243s, I found one from the earliest days of broadcast radio. The Philmore Fixed Crystal Detector is really just a chunk of galena with a phosphor bronze cat whisker held in place by a spring. Philmore apparently went ahead and found a "sweet spot" for you.

Sunday, June 4, 2017

A link to the .asc LTSpice file for the NE602 rig appears below. Perhaps some brave soul more skilled in LTSpice than I am might want to turn this drawing into a real simulation. Some of the parts (like the NE602s) have actual simulated components behind the drawings. Others (like the relays and the LM741 and LM386) are just drawings. But go ahead and flesh this thing out. Who knows, it might come to life in the PC and start making QSOs on 40!

Saturday, June 3, 2017

This is a rig that came together through a process of Spontaneous Construction. It started out with an innocent effort to get an Organic Light Emitting Diode display to work with an Si5351/Arduino combination. Then I figured I'd make a superhet receiver with it. Then Pete said I should make it a transceiver. Most of my earlier transceivers so closely followed the schematics of Farhan or others that it didn't really make sense for me to prepare a new schematic. This one was different. So I decided to prepare a proper schematic. I tried a few of the free-ware CAD or drawing programs, but each of them had a learning curve at the entrance. So I turned to LTSPICE. I have already climbed that learning curve. The results appear above. Click on the image to make it bigger. I'm sure there are errors in there. And I think some of my parts choices might be less than optimal. But it works well. The filter was deigned with the help of AADE software. The idea of using two NE602s with a filter between them came (I think) from the Epiphyte. The band pass filters were designed with ELSIE software. The RF power chain is mostly from Farhan's BITX40 module, with the pre-driver and driver modified for a bit more gain. Farhan's amp is the most stable power amplifier I have ever used. It hasn't given me any trouble, even at 20 Watts. Strongly recommended. The microphone amp is derived from the 741 op amp circuit used in the (in)famous Wee-Willy DSB rig. The receiver AF amp also comes from Farhan's BITX40Module.

Please let me know if you spot errors or have suggestions for circuit improvement.

A link to the .asc LTSpice file appears below. Perhaps some brave soul more skilled in LTSpice than I am might want to turn this drawing into an actual simulation. Some of the parts (like the NE602s) have actual simulated components behind the drawings. Others (like the relays and the LM741 and LM386) are just drawings. But go ahead and flesh this thing out. Who knows, it might come to life in the PC and start making QSOs on 40!

Thursday, June 1, 2017

Bob, KY3R, here. Haven't written to you in a few years (although do manage to run into you most years at the Vienna Wireless Society hamfest ).

Anyway, was watching your visit with Farhan, and you mentioned your penchant for building projects into wooden hobby boxes, and using copper flashing for shielding. I want to share my solution.

I snatched up any old cigar boxes I come across. For shielding I use "metal repair tape." This is the stuff used for joining or repairing dryer lint vent ducts, and it is available at any hardware store. Very lightweight, and you just cut the desired lengths, peel off the backing, and press onto the inside of the box. The only drawback is that it is aluminum and doesn't take solder very well, but it is easy enough to add one or two short lengths of wire from the circuit ground plane to a terminal bolted down onto the case interior.

The attached photos show my current project--a Por Larranaga cigar box in the process of being converted into a home for a BitX-40! I haven't yet fully decided exactly how to position the unit in the box, but as shown in one of the photos, it fits with plenty of room for later mods. As for other decisions, I toyed with the idea of painting or covering the outer box, but I am leasing toward leaving the original cigar box labeling. Arguably adds a bit of "soul," plus who needs a clean panel and all that fancy stenciled lettering anyway. I'll know which knob is which!

73, and as always, thanks to you (and Pete, of course) for your continued work on the SS podcast.

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